Terrain Compound Object
 
 
 
Bottom of the Page

Select spline contours. Create panel (Geometry) Compound Objects Object Type rollout Terrain

Select spline contours. Create menu Compound Terrain

The Terrain button lets you produce terrain objects. 3ds Max Design generates these objects from contour line data.

To create Terrain, you select editable splines representing elevation contours and create a mesh surface over the contours. You can also create a "terraced" representation of the terrain object so that each level of contour data is a step, resembling traditional study models of land forms.

Using contours to build a terrain

Upper left: The contours

Upper right: The terrain object

Lower left: Terrain object used as the basis of a landscape

If you import an AutoCAD drawing file to use as contour data, 3ds Max Design names each object based on the AutoCAD object's layer, color, or object type. A number is appended to each name. For example, an AutoCAD object on the layer BASE becomes an object named BASE.01. See Importing DWG Files for more information.

After you import or create the contour data, select the objects, and click the Terrain button, 3ds Max Design creates a new triangulated mesh object based on the contour data. The name of the first selected spline becomes the name of the terrain object. Other splines in the selection are treated according to the previously set Reference, Move, Copy, or Instance selection in the Pick Operand rollout, described below.

Keep in mind that the Terrain object can use any spline objects as operands, whether they are horizontal splines or not. Though the most common scenario is when sets of elevational contours are used to create terrain forms, it is possible to append or refine Terrain objects by using non-horizontal splines.

NoteTo ensure that 3ds Max Design imports polylines as splines, when you import an AutoCAD drawing file, turn off Import AutoCAD DWG File dialog Geometry Options group Cap Closed Entities.

Following are examples of uses of the Terrain feature:

Procedures

To analyze elevation changes:

  1. Import or create contour data.
  2. Select the contour data, then click the Terrain button.
  3. On the Color By Elevation rollout, enter elevation zone values between the maximum and minimum elevations in the Base Elev box. Click Add Zone after entering the value.

    3ds Max Design displays the zones in the list under the Create Defaults button.

  4. Click the Base Color swatch to change the color of each elevation zone. For example, you could use a deep blue for low elevations, a light blue for intermediate elevations, and perhaps greens for higher elevations.
  5. Click Solid To Top of Zone to see the elevation changes in a striped effect.
  6. Click Blend To Color Above to see the elevation changes blended.

Interface

Name and Color rollout

Displays the name of the terrain object. 3ds Max Design uses the name of one of the selected objects to name the terrain object.

Pick Operand rollout

Pick Operand

Adds splines to the terrain object. You might do this if you didn't select all the objects before generating the terrain object, or if some objects in the imported data weren't included in the terrain object. You can also use this option to add existing splines in the current scene to the terrain object.

Reference/Copy/Move/Instance

When you click Pick Operand, the copy method you designate determines how the operands are used. When Move is the method, the original contour data is moved from the scene and into the operands of the new terrain object. Copy, Reference, and Instance retain the original contour data in the scene and create copies, references or instances of the contour data as operands in the terrain object. This is similar to the copy method for Boolean.

Override

Allows you to select closed curves that override any other operand data within their interior. Within the area an Override operand encloses (as seen in plan), other curves and points of the mesh are disregarded and the elevation of the Override operand supersedes them. An Override operand is indicated in the operands list by a # after its name. Override is only effective on closed curves. If multiple override operands overlap, later overrides (higher operand numbers) take preference.

Parameters rollout

Operands group

Operand list

Displays the current operands. Each operand is listed as "Op" followed by a number and the name of the object that is being used as the operand. The operand name comprises layer, color, or object type name plus a numeric suffix.

Delete Operand

Deletes a selected operand from the Operands list.

Form group

  • Graded SurfaceCreates a graded surface of the mesh over the contours.

    Terrain created as a graded surface

  • Graded SolidCreates a graded surface with skirts around the sides and a bottom surface. This represents a solid that is visible from every direction.
  • Layered SolidCreates a "wedding cake" or laminated solid similar to cardboard architectural models.

    Terrain created as a "layered solid" surface, with levels

Stitch Border

When on, suppresses the creation of new triangles around the edges of terrain objects when edge conditions are defined by splines that are not closed. Most terrain forms display more reasonably when this is turned off.

Retriangulate

The basic Terrain algorithm tends to flatten or notch contours when they turn sharply upon themselves. A typical situation in which this may happen is when a narrow creek bed is described with contours; the resulting form may look more like a series of cascades at each elevational contour, rather than a smoothly descending ravine. When Retriangulate is checked, a somewhat slower algorithm is used that follows contour lines more closely. This may be particularly evident in the Layered Solid display mode. For additional precision, try using Retriangulate in conjunction with horizontal interpolation.

Display group

  • TerrainDisplays only the triangulated mesh over the contour line data.
  • ContoursDisplays only the contour line data of the terrain object.
  • BothDisplays both the triangulated mesh and the contour line data of the terrain object. You can select the terrain object by clicking its surface, but not by clicking a contour line. When Both is selected, contour lines may not be apparent in Wireframe display modes or when Edged Faces are displayed.

Update group

The items in this group box determine when 3ds Max Design recalculates the projection for the terrain object. Because complex terrain objects can slow performance, you can use these options to avoid constant calculation.

  • AlwaysUpdates the terrain object immediately when you change an operand, including the original object of an instanced or referenced operand.
  • When RenderingUpdates the terrain object when you render the scene or when you click Update. With this option, viewports won't show current geometry unless you click Update.
  • ManuallyUpdates the terrain object when you click Update.
Update

Updates the terrain object. This button is not enabled only when Always is the active option.

Simplification rollout

Horizontal group

  • No SimplificationUses all the operands' vertices to create a complex mesh. This results in greater detail and a larger file size than the two fractional options.
  • Use 1/2 of PointsUses half the set of vertices in the operands to create a less complex mesh. This results in less detail and a smaller file size than using No Simplification.
  • Use 1/4 of PointsUses a quarter of the of vertices in the operands to create a less complex mesh. This results in the least detail and smallest file size of these options.
  • Interpolate Points * 2Doubles the set of vertices in the operands to create a more refined but more complex mesh. This is most effective in terrain forms that use constructive curves such as circles and ellipses. This results in more detail and a larger file size than using No Simplification.
  • Interpolate Points * 4Quadruples the set of vertices in the operands to create a more refined but more complex mesh. This is most effective in terrain forms that use constructive curves such as circles and ellipses. This results in more detail and a larger file size than using No Simplification.

Vertical group

  • No SimplificationUses all the spline operandsvertices of the terrain object to create a complex mesh. This results in greater detail and a larger file size than the other two options.
  • Use 1/2 of LinesUses half the set of spline operands of the terrain object to create a less complex mesh. This results in less detail and a smaller file size than using No Simplification.
  • Use 1/4 of LinesUses a quarter of the of spline operands of the terrain object to create a less complex mesh. This results in the least detail and smallest file size of the three options.

Color by Elevation rollout

Maximum Elev.

Displays the maximum elevation in the Z axis of the terrain object. 3ds Max Design derives this data from the contour data.

Minimum Elev.

Displays the minimum elevation in the Z axis of the terrain object. 3ds Max Design derives this data from the contour data.

Reference Elev.

This is the reference elevation, or datum, that 3ds Max Design uses as a guide for assigning colors to zones of elevation. After entering a reference elevation, click the Create Defaults button. 3ds Max Design treats elevations above the reference elevation as solid land and those below the reference elevation as water.

If you enter a value no greater than the minimum elevation in the object, 3ds Max Design divides the range between the reference and minimum elevations into five color zones: dark green, light green, yellow, purple, and light gray.

If you enter a value between the minimum and maximum elevations, 3ds Max Design creates six color zones. Two zones (dark blue and light blue) are used for elevations below the reference elevation. These are considered to be under water. One zone (dark yellow) is used for a narrow range around the reference elevation. Three zones (dark green, light green, light yellow) are used for elevations above the reference elevation.

If you enter a value at or above the maximum elevation, 3ds Max Design divides the range between the minimum and reference elevations into three zones (dark blue, medium blue, light blue).

Zones by Base Elevation group

Create Defaults

Creates elevation zones. 3ds Max Design lists the elevation at the bottom of each zone, referenced to the datum (the reference elevation). 3ds Max Design applies the color of the zone at the base elevation. Whether the colors blend between zones depends on your choice of the Blend to Color Above or Solid to Top of Zone option.

Color Zone group

The items in this group box assign colors to elevation zones. For example, you might want to change levels of blue to indicate the depth for water. Your changes in the Color Zone area don't affect the terrain object until you click the Modify Zone or Add Zone button.

Base Elev

This is the base elevation of a zone to which you assign color. After entering a value, click Add Zone to display the elevation in the list under Create Defaults.

Base Color

Click the color swatch to change the color of the zone.

  • Blend to Color AboveBlends the color of the current zone to the color of the zone above it.
  • Solid to Top of ZoneMakes a solid color at the top of the zone without blending to the color of the zone above it.
Modify Zone

Modifies selected options of a zone.

Add Zone

Adds values and selected options for a new zone.

Delete Zone

Deletes a selected zone.